Remapping
of engine control software for better performance
The software control parameters of electronic engine management systems are stored
within the vehicle on board computer as a
"map".
Vehicle manufacturers software is often programmed to provide low emissions
and driveability over a wide range of
operating conditions.

Performance upgrades are
available which allow specific changes to the original software to meet individual driving requirements.

Driving cycle and engine control mapping

Vehicle driving cycles have a huge impact on the type and frequency of servicing needed.
Vehicles operating on frequent short journeys may not reach normal operating temperature before stopping and may also suffer
from battery charging system problems.

Exhaust gas recirculation fitted to many vehicles can cause build up of carbon and sludge deposits in engine intake manifolds. Blockages
and restrictions lead to malfunction of items such as idle speed control motor ,throttle flap,and EGR valve etc causing driveability problems.

Competition vehicles developed to compete in motorsport may be operated with modified engine control software maps written to provide increased fuelling
and power output often at the expense of driveability.

The inputs are carried along wires to a central computer, (ecu) where the received signals are processed
and compared to
programmed values stored as a memory map, then output values calculated and sent along wires to
output actuators such as fuel injectors,
control pressure regulator , cooling
fan, idle speed control ,etc, to maintain
performance factors such as smooth engine running,
fuel economy, and low exhaust emissions.

What causes problems with engine management?

Various things can affect the efficient running of your vehicle:

Vibration

of the engine or vehicle body can cause wiring harnesses and pipes to move and chaff against other components
leading to wiring insulation damage , and eventually corrosion or breakage of wires.
Damaged wiring insulation may cause a short
circuit between power and signal or ground
wiring.

Road salt and moisture can enter wiring connections leading to corrosion
, high resistance, and low voltage faults.

A scan tool test to retrieve fault codes
stored as history by the vehicle computer may
indicate a component low
voltage or open circuit or short circuit code identifying the area the where
a fault exists.
Fault codes outputted to the scantool via serial data may be manufacturer specific or generic (EOBD)
Taking a typical P0100 fault code as an example, the fault code relates to Mass Air Flow Sensor circuit malfunction.
This P0100 code could have many causes for example , broken wiring or bad connection to the airflow sensor, slow response time from the sensor itself,
a fault on the engine control unit board causing loss of connection, insufficient air flow past the sensor due to leaking pipework or low performance from a turbocharger.
An immediate response from many technicians would be to change the airflow sensor, however, if the fault is an effect of a different cause this would simply be wasted money!
Scantools do not fix faults, they read data from the control unit and in some cases have further functions such as actuator testing and adaptation of parameters.
Further testing will almost certainly be needed to identify the exact location of the fault if broken or damaged wiring exists.

Build up of carbon deposits due to the
operation of exhaust gas recirculation systems can also cause problems with air intake

Fuel quality will affect component life. Moisture or contamination in fuel can lead to corrosion which may be detrimental
to precision machined
components particularly in high pressure fuel injection systems.
Signs of failure can be metal particles in the fuel filter or fuel tank indicating component wear.

Manufacturer Software Updates

Despite extensive testing, when manufacturers develop a new vehicle model there may be unforeseen problems which only show after the effects of particular in service wear and tear.
These problems which develop may affect exhaust emissions or driveability can sometimes only be corrected be updating the control unit software,
in similar fashion to updating the drivers on a pc.

The type of microcontroller chip inside the control module will determine the method required to update software.
In some cases this may require replacement of the program microchip ,
but on later vehicles updated software may be 'flash' programmed via the diagnostic connector using a pass-thru programming technique.

Certain faults which occur to a particular vehicle model may alert the manufacturer to release a TSB or Technical Service Bulletin.

Updated calibration software is downloaded from the vehicle manufacturers website and transferred to the vehicle computer using either a dedicated tool
or a computer and SAE J2534 (refers to Society of Automotive Engineers protocol) compliant interface

Vehicle Computerised Diagnostics

Mobile service for car electrics repair

Telford, Shrewsbury and Shropshire surrounding areas.

Telephone 07703 558610 for booking.

Computerised vehicle diagnostics is a means of using the ability of the vehicle computer
control system to
monitor the condition of vehicle components.

Historical fault codesIntermittent faults which occur during driving
may be logged as an error fault code
which causes the dashboard warning
light to illuminate.

Random disconnecting of electrical connectors in the engine bay may also cause
fault codes to be logged.

Retrieval of fault codes

Most modern vehicles require diagnostic equipment with
dedicated
software to interrogate the
relevant control module for
stored fault codes.
Automotive system electrical diagnostics
involves an interrogation scan of the vehicle computer for stored fault
codes using suitable diagnostic equipment such as a scan tool fault code reader.

Some older vehicles (usually Japanese) have a self diagnosis function allowing the the fault code to be read by counting the
flashes of the check
engine light and looking up the value in a reference table.

Test and Repair

Following testing, a faulty wiring circuit may be repaired or component cleaned or replaced.

Diagnostic Equipment FunctionsOur diagnostic equipment is capable of

Fault code reading

Actuator testing

to verify wiring circuits
by operating the suspect component on a wide range of vehicle systems.
The actuator test function can allow some components
to be thoroughly cleaned which may save replacement cost.

Programming and Coding

Some
components such as electronic fuel
injectors , throttle bodies etc may need coding to the vehicle ecu

Advanced system testing can be
carried out using oscilloscope
signal test methods

Reset Procedures

Following repair work the fault code memory of the vehicle computer will need to be reset to clear stored fault codes.

Diagnostic Training

Automotive diagnostics involves
more than just plugging in a scan tool to read fault codes.

Diagnostic error codes provide a clue as to what the control system
recognises as a fault but remember it
is an electro mechanical system which
is under repair.

Motor trade industry experience
combined with investment and continuing professional
development of staff through a system
manufacturer
training
courses aids vehicle system diagnosis
& repair.

Snap On Diagnostic equipment with regularly updated software for modern vehicles
is one of a range of tools which provides Fault code reading, Fault code clearing, Actuator
testing, ECU interrogation for live data.
Diagnostic testing available in Telford & Shrewsbury
Shropshire areas.